The ongoing historic drought has had many negative consequences for Marin County so far, but it has produced one short-term benefit: clean beach water during the summer.
Twenty-four beaches tested in Marin County received a straight-A grade for water quality during the summer of 2020 as part of the latest beach report card Released by Heal the Bay, a Santa Monica-based environmental group. The organization grades beaches based on the concentration of fecal bacterial contamination, such as E. coli, which can indicate the potential presence of harmful pathogens.
According to water quality officials, 93% of the 500 statewide beaches assessed in the report that received high marks for the summer of 2020 had Marin’s beaches, meaning below average summer rainfall.
“This reduced the amount of pollutants flowing into the ocean,” said Aarti Kundu, chief of the beach water quality testing program for the Marin County Environmental Health Division. “We have always improved the water quality whenever there is a drought or a decrease in rainfall.”
The reverse scenario also emerges. Heavy rains during the winter months lead to a greater influx of pollutants onto the beaches.
However, Marin does not conduct water quality tests during the November winter period until late March, since it began a beach monitoring program in 2003, Kundu said. This is because of state grants that fund these beach water trials, Kundu said.
To qualify for funding, the tested beaches must meet a number of criteria. It should be used by 50,000 people per year for recreational purposes in which people regularly come into contact with water, such as swimming, and have an identified source of contamination such as sewage systems.
The winter months generally see a significant reduction in beach visitors and entertainment.
“That’s the main reason we stay during the winter months,” Kundu said.
According to Heal the Bay, for California beaches that were tested during the winter months, the grades were worse than average.
Generally, a significantly dry winter such as that occurred in 2020-21 will lead to less pollutant runoff. The group attributes this unusual phenomenon to receiving 1,500 fewer water samples than normal, which it says could dilute the results. A more important factor is that drought left people less likely to test for winter water quality, so several tests were conducted during the first major flush of rain that contained high concentrations of bacteria.
This was seen in several places in Point Reyes National Seashore near the dairy farm last winter. Environmental group Western Watershed Project contracted two days of water quality tests after the first major rain in January and bacteria levels were found 300 times bigger than state health standards in one place. The group attributes this contamination to nearby ranching operations that lease land in the national park.
The National Park Service stopped testing those sites in 2013. Park employees have said that the farms have experienced significant reductions in runoff pollution since that time, but said it is considering plans to restart those testing efforts and submit potential testing plans. For the California Coastal Commission within the next year.
Meanwhile, West Marin’s Environmental Action Coalition is working to fill in data gaps at three unused beaches at Point Reyes National Seashore: Limantaur Beach, Drax Beach and a kayak drop at Drax Estero. The environmental organization’s executive director, Morgan Patton, said the National Park Service stopped testing these sites several years ago and is no longer including the locations on report cards.
Patton said his organization decided to conduct trials only last winter and test Drax Beach and Drax Estero from October to March, using funds raised by its members and the same methods used by the county. The group plans to restart the program at all three locations in September.
“It’s really a community grassroots effort to make this happen,” Patton said.
Water quality experts such as Patton and Kundu say many years of water quality data are needed to draw conclusions and determine trends.
In the meantime, Patton said he is looking forward to seeing what the National Park Service proposes to the Coastal Commission.
“If people are concerned about whether there are pathogens or bacteria in the water it will be very important to really take a closer look at what the Park Service does next,” Patton said.
The Beach Report Card also reported that Marin reported 11 spills during 2020-2021 affecting approximately 110,000 gallons of sewage local water bodies, most of which came from about one. 95,000-gallon spread at Sausalito in April.
A copy of the Beach Report Card can be found here bit.ly/376KfR3.